Method of building joints



Jan. 11 v M.

METHOD OF BUILDINQ JOINTS Filed Oct. 5, 1925 2 Sheets-Sheet l bvvavroz w/ 7'A/E68E5 807M411; in. 3mm

7 1,613,911 1927 D. M. SIMOYNS METHOD OF BUILDING JOINTS Filed D et. 5.. 1925 2 Sheets-Shasta wvavrara TN 8353 I E W 3M4- 071,6

Patented Jan. 11, 1921.

UNITED (STATES PATENT OFFICE.)

DONALD M. SIMON S, OF OSBORNE, PENNSYLVANIA, ASSIGNOR TO STANDARD UNDER GROUND CABLE COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF.

PENNSYLVANIA.

METHOD or BUILDINGJOINTS.

Application filed October 3, 1925. Serial No. 60.330.

1 My invention relates to the installation of electric cables, and consists in improvements in methods of-b uilding joints.

An oil-filled cable is one whose installation consists of or contains material which at the temperature of installation is fluid. This fluid material may be present in the cable structure as a free body or layer of installation, or it may be present in association with .other insulation; for instance, it may be more or less completely absorbed by a body of porous or fibrous insulation. In the building of cables -for. particular kinds and conditions of service, it is in some cases desirable, for electrical reasons, to

use insulating compound which even at ordinary temperatures is liquid; or, aga n, a given cab e containing a compound which at ordinary atmospheric temperature would not flow, may be installed in a hot country or in a hot location, and at a temperature at which the compound would flow. I cite as an instance of an oil-filled cable, but only as an instance, and not by way of limitation, the cable shown and described in Letters Patent of the United States No. 1,574,076,

granted February 23, 1926, on the application of Henry W. Fisher.

In making installation of an oil-filled cable, it is necessary that there be no escape of the insulating compound, whether it be present as a free body of oil, or as a body more or less completely absorbed in a body of porous or fibrous insulation. And, specifically, in jointing together successive lengths of oil-filled cable, it is necessary that there be no running away of the fluid insulation, when the outer covering of'the cable is removed.

My invention maybe practiced in the operation of apparatus shown in the accompanyin drawings. Fig. I is a view in vertical an medial section through a. certain tank, showing in elevation'certain contained mechanism; Fig. II is a view in transverse section, on the broken plane indicated at IIII, Fig. I; Fig. III is a diagrammatic showing, in illustration of a certain step in procedure; Fig. IV is a view in perspective of a certain sleeve; Fig. V is a diagrammatic illustration of'a certain step in the procedure.

I have for purposes of illustration shown as incidental to the practice of my invention,

\ the joint-building machine shown and described in Letters Patent of the United States No. 1,585,127, granted May 18, 1926, on the application of myself jointly with Frank D. Barbour. This joint-building machine includes a drum 1, borne in a suitable frame 2 and rotatable on'its axis. The drum is axially perforate and the frame is provided with clamping members 3, adapted to engage two cable ends 4, and to hold them securewhilea joint is being built between and upon them. The drum carries a spool 5, upon which a web of sheetin; sulation is wound, and from which in the operation ofthe machine the sheet of -insulation istaken and"wrapped upon the united cable ends. Such a machine may conveniently be employed in the practice of my present invention.

This machine in the practice of my present invention is contained within a tank 8v with a removable lid 9. The tank is such in character as to receive and contain a' body of oil, submerging the drum at least to a point above its axis, and submerging a cable in place previously brought to the drum.

Through a properly packed orifice in the Wall of the tank, the crankshaft 10 extends, by means of which the drum is rotated. The tank in its end walls is provided with deep notches or recesses,-in which closure plates 11 are removably secured, and these closure plates are adapted to be united to the tank- Walls in liquid-tight union. The end walls and the closure plates 11 are provided with companion half-cylindrical sleeves 12 and 13, which when a cable is in place and the plates 11 are in'place, may be clamped in liquid-tight engagement one upon another, and each upon the outer surface of an introduced cable-body 4. The tank may.nd ditionally be provided with connections for the introduction of and the drawingofl of oil; but, since such provisions are in no sense essential to normal operation, I do not show them. Y

My invention has to do, as I have said, with the jointing of oil-filled cables. Such cables when prepared for laying are sealed at the ends. When a joint is to be made,

the seal is necessarily broken. and the {Help len is, how to op n the nds. elteet the union. and complete the joint. without es cape of oil and consequent ingress of air to the cable structure.

in the practice ol' my invention I open the sealed cable ends under oil, ellect under oilthe electrical union of the conductors. and while still under oil enclose the union properly insulated in a liquid-tight and 111echanically secure joint structure, and then remove the joint t'rom immersion. it may then he in finished condition. or further building may be done to n'ender the joint fu ly and permanently serviceable. 1 shall describe in detail a particular procedure.

Referring, first, to Fig. Hi. provide a union for the cable conductor itself. such as is shown and described in Letters Patent of the United States No. 1,579,494, granted April 6, 1926, on my application. It consists essentially of two thimbles (3 and a uniting body 7. The thimbles are socketed and are adapted to be electrically united, as by being sweated to place, upon the ends of the cable conductors, and the two thimbles which constitute a pair and the companion uniting body are screw-threaded, and the ends of the two engagements are oppositely turned, so that when the uniting body is brought between the axially aligned thimbles, rotation of the uniting body will effect the union.

In Fig. HI two cable ends to be united are indicated at -11. Let it be understood that these are ends of lengths of oil-filled cable, and that a joint is to be made between thena. The ends, of course, are initially sealed. In the practice of my invention I conveniently proceed in the following manner. I first turn these ends to the vertical position indicated. and while they are in such position, I remove the seal, cut away sheath and insnlation to expose the conductor-ends sutticiently. Upon the exposed conductor ends I sweat the two thimbles (3 of the union, whose character I have indicated. 1 then cap the cable ends again. The cap may be a tight-fitting rubber cap, bound around the cable-ends and around the thimbles secured thereto, or it may be any suitable cap whieh will form a secure closure ot the cable end again, preventative ot the escape of oil and ot' the ingress of air into the cable structure.

While. still the cable ends are accessible, the sheath may be scored and partially cut through. where complete cutting-away is to he etlected. incidentally to the building of the joint.

\l'hen these preliminary steps have been taken. the cable ends bent straight again may be introduced to the jointbuilding machine. particularly illustrated in Figs. 1 and ii. The tank is at this time empty and the closure plates are removed. The cable ends, introduced into the machine, are brought to position. and are lamped to pla e in the 'lrame .2 by the application and the securing ol' the clamping plates 21. The closure plates ll of the end walls ol' \he tank are then brought to position and secured. and when this has been done the tank walls will he closed in liquid-tight engagement arc-und the cable bodies 1. Oil is then introduced and the tank isiilled. to the extent at least that. the included cable ends are completely submerged.

is I have said in i ictters Patent No. 1,585.12? mentioned above. and as the drawings in this case clearly indicate, the apparatus here shown is intended for field servictx for joint-building is essentially a field opera-' tion. The oil-then, which ordimnily will be clean, dry transformer oil. will be available. borne by truck. and, when the apparatus is ready, the truck is drawn up and the oil is run in.

l l hen the cable-ends within the tank have so been submerged in oil, the rubler caps or other temporary closures are taken away, the uniting body 7 is brought to position and screwed to place, uniting electrically the two conductor ends.

The score cuts in the lead sheath are then cut through, and the cut-away lead is removed. It is (onvenient that, up to this point at least in the progress of the operation, the volume of oil within the tank be little more than snfiicient to submerge the cable ends. The cutting then may be done by plunging no more than the end of the tool beneath the surface of the oil.

I have described the trimming away of .the cable sheath by hand. Instead, the drum equipped with knives, as described in Letters Patent No. 1,585,127, may be employed, to cut the sheath and the underlying machinelaid insulation as well.

When the drum is to be brought into operation, whether to trim the cable ends or to apply the wrapping of paper in building outthe joint, or both, the depth of oil within the tank may be increased to the desired maximum.

The wrapping on of paper around the united conductor ends and between the cut away ends of machine-laid insulation and of cable sheath, and the building out to larger diameter of an envelope of wrappedon paper. bearing liarmg screens ot conduct- 111g materlal electrically continuous with the cut-away ends of the. cable sheath. are matters tully describedin the specification of Letters Patent No. 1.58:"),197, and these matters in their details are not part of my present invention. Sullice it to say here'that the united conductor ends are, while submerged in insulating liquid. suitably covered by a permanently applied body of insulation: and that, in the. operation of the machine which here is shown by way of exion ill)

ample. this permanently applied body of insulation consists in a wrappingof paper or other suitable material.

Incidental to or sequent upon the enveloping of the united conductors within a permanently applied body of insulation. a split metallic sleeve. such as'that indicated at 14, Fig. IV. may be applied under oil. and bolt cd' to place. elfecting liquid-tight closure. around the joint'and upon the cable sheath at either side and adjacent the-joint. The

oil within the tank and external to the sleeve may now be drawn off, and the cable with the thus far completed joint may be removed from the machine and from the tank-or, as commonly will be the fact, tank and machine aretaken away from the joints installations the" ed cable. For certain structure thus far described constitutes a completed joint. Ordinarily, however, an outer sleeve is ap )lied. This outer sleeve may be the familiar lead sleeve, initially slipped over one of the cable ends, and now brought to place, shaped at the end, and united by wiped-solder joint to the cable sheath on either side of the union. This outer sleeve. however, may be formed and applied as desired. p

The space between inner and outer sleeves will ordinarlly be filled with insulating material, applied in liquid condition. If it be desired to provide the joint with a reservoir of liquid insulation (a provision well known to the art,) a pi e may be provided, ex-

- tending from wit in through both of the pleted job.

Electric lights may be provided within the tank and, during operation, submerged, to afford illumination. The tank may be heated by suitable means, to-bring to desired condition of fluidity a 'more viscid insu lating oil, or for other purposes. In such case the cutting of cable sheath and of machine-laid insulation may be effected either by mechanically operated knives or by knives held manually aboi e but with cutting blades thrust beneath the surface of the oil. If in'its planetary movement the roll of "paper upon the spool of the machine be caused alternately to emerge'from and to plunge again into the bath of oil, the direction of winding of the aper on the spool will preferably be such tiiat the formation of an air pocket is avoided between the roll of paper stillon the spool and the web which is being drawn in tangential path from it. This point isillustratedin Fig. V, in which the direction of swing of the spool 5 in its.

orbit around the cable structure 4,-is indicated by an arrow. The surface of the bath of oil is indicated by the dotted line (6--t)..

And it will be observed that as the spool 5 plunges beneath the surface no such air pocket is formed as would be the case at the point 0, were the direction of rotation rcversed.

If, instead of the procedure last indicat-- ed, in which the spool of paper alternately plunges into and rises from the bath of oil,

the whole drum be submerged and the whole wrapping operation be performed under oil,

it will be desirable to provide a roll of paper filled with oil to the exclusion of air. A roll in such condition manifestly may be prepared and may be enclosed in a liquidtight tube or other closure. In such condition it may be brought to the tank' and submerged in the bath of oil. After submergence the closure may be removed and the roll may be* secured in its place.

I claim as my invention 1. The method herein described of joint- 7 ing an oil-filled cable which consists in immersing in oil two cable ends, opening under oil the cable ends so immersed, effecting under oil electrical union of the cable conductors, enclosing the union while still under oil in an insulating li uid-tight structure, and removing the joint. I'OIIl immersion.

2. The method herein described of jointing an oil-filled cable which consists in immersing in oil two cable-ends, opening under oil the cable ends so immersed, effecting under oil electrical union of the cable conductors, wrapping the union under oil with insulation, enclosing the wrapped joint in a liquid-tight casing. and removing the struc- I ture from immersion.

. 3'. The method herein described of jointing an oil-filled cable which consists in bringing the sealed cable-end to vertical position, unsealing the end and electrically uniting to the conductor end a. union-affording thimble, sealing the end again, immersing the rescaled cable-end in oil and bringing it under oil to alignment with another condu ctor, removing the seal under oil and electrically uniting the thimble to the other conductor, enclosing the union while still-under oil in an insulating liquid-tight structure, and removing the joint from immersion.

4. The method herein described of jointing oil-filled cables which consists in bringing the sealed cable-ends to be united to vertical position, unsealing the ends and electrically uniting to the conductor ends union-affording thimbles, sealing the ends again, immersing the re-sealed cable-ends in oil and bringing them to alignment under oil, removing the seals and electrically uniting the thimhles wrapping the union under oil with sheet insulation, enrlosing, the wrap peril union in an nil-tight easing which engages thewuble sheath at either side, and removing the whole from immersion.

The method herein described of joint in; oil-filled cables which consists in bringing; the sealed cable-ends to be united to vertical position, unsealing the ends and electrically uniting to the exposed conductor ends-union-affording thimbles, sealing: the ends again, immersing the ire-sealed cable-ends in oil and hringing them to alignment under 0il re1novin the seals and electrically uniting the thinihles. Wrapping the union under oil with sheet iln'ulutioin enclosing the wrapped union in nu oil-tight elosure. removing the structure from innnersion. surrounding the whole in a joint casing and securing the joint easing at either end to the euhle sheath on either side of the joint.

In testimony whereof I have hereunto set my hand.

DONALD M. SIMONS. 

